Oecetis dilata, Wells, 2004

Wells, Alice, 2004, The long-horned caddisfly genus Oecetis (Trichoptera: Leptoceridae) in Australia: two new species groups and 17 new species, Memoirs of Museum Victoria 61 (1), pp. 85-110 : 98-99

Oecetis dilata sp. nov.

Figures 57–59, 119

Material examined. Holotype, male,WA, 9 km N of Kununurra , 19 Sep 1979, J. Blyth ( NMV T-18514).

Paratypes.WA: 3 males, 2 female, same data as for holotype ( NMV) ; 2 males, Geikie Gorge , 18°06'S 125°42'E, 5 Oct 1996, I. Edwards ( NMV) . Qld : 2 males, female, McLeod River, 15 km W of Mt Carbine, 22–23 Jun 1975, S.R. Monteith ( ANIC) ; 2 males, Cape York Peninsula , Laura, 15°33.9'S 144°27.1'E, 7 Oct 1979, M.S. and B.J. Moulds ( NMV) ; 2 males, 2 females, 11°08'S 142°21'E, Jardine River , 19 Oct 1992, P. Zborowski and T. Weir ( ANIC) . NT: 2 males, Daly River , 13°45'S 132°42'E, 9–10 Aug 1980, M.B. Malipatil ( NMV) .

Diagnosis. Forewing length about 4 times maximum width, footstalk present on fork 1, t1 more distal than t2 or t3. Males genitalic features, inferior appendages, in ventral view have width about 0.75 times length, and are rounded towards the apex, with a small apicolateral lobe, and in lateral view, have length about 4 times width.

Description. Spurs 1, 2, 2. Male forewing length 4.8–5.4 mm. Forewing with footstalk on fork 1 slightly shorter than fork; posterior anastomosis stepped with t1 more distal than t2, t3 oblique, slightly distad of t2. Male genitalia, Figs 57–59. Segment IX uniformly narrow, preanal appendages ovoid, widely separated. Segment X simple broad, apically truncate. Inferior appendages stout, apically rounded with short, thin lobe laterally; narrow and straight in lateral view, rounded apically. Phallus stout, rounded, strongly curved downwards.

Distribution. Far northern Qld, NT and WA (Fig. 119).

Etymology. Latin, dilata — enlarge, for the unusually broad inferior appendages.